Download to read offline
More Related Content
Encoder
- 1.
- 2. SLIDESMANIA.COM What is Encoder? •Combinational circuit • Performs the reverse operation of Decoder • Maximum of 2𝑛 input lines and 𝑛 output lines ENCODER 2 𝑛 INPUTS 𝑛 OUTPUTS
- 3. SLIDESMANIA.COM Generates an outputbased on the highest prioritized input Binary Priority Converts one of 2𝑛 inputs into an 𝑛 bit output
- 4. SLIDESMANIA.COM 4 – 2Encoder 4 inputs: 𝒀𝟑, 𝒀𝟐, 𝒀𝟏, 𝒀𝟎 2 outputs: 𝑨𝟏, 𝑨𝟎 4 - 2 ENCODER 𝒀𝟑 𝒀𝟏 𝑨𝟏 𝒀𝟎 𝒀𝟐 𝑨𝟎 Block diagram
- 5. SLIDESMANIA.COM 4 – 2Encoder 4 inputs: 𝒀𝟑, 𝒀𝟐, 𝒀𝟏, 𝒀𝟎 2 outputs: 𝑨𝟏, 𝑨𝟎 4 - 2 ENCODER 0 1 0 0 0 1 Block diagram
- 6. SLIDESMANIA.COM INPUTS OUTPUTS 𝑌3 𝑌2𝑌1 𝑌0 𝐴1 𝐴0 0 0 0 1 0 0 0 0 1 0 0 1 0 1 0 0 1 0 1 0 0 0 1 1 4 – 2 Encoder Truth Table
- 7. SLIDESMANIA.COM INPUTS OUTPUTS 𝑌3 𝑌2𝑌1 𝑌0 𝐴1 𝐴0 0 0 0 1 0 0 0 0 1 0 0 1 0 1 0 0 1 0 1 0 0 0 1 1 4 – 2 Encoder Truth Table 𝐴1 = 𝑌3 + 𝑌2
- 8. SLIDESMANIA.COM INPUTS OUTPUTS 𝑌3 𝑌2𝑌1 𝑌0 𝐴1 𝐴0 0 0 0 1 0 0 0 0 1 0 0 1 0 1 0 0 1 0 1 0 0 0 1 1 4 – 2 Encoder Truth Table 𝐴0 = 𝑌3 + 𝑌1
- 9. SLIDESMANIA.COM Boolean functions 𝐴1 =𝑌3 + 𝑌2 𝐴0 = 𝑌3 + 𝑌1 Circuit diagram
- 10. SLIDESMANIA.COM 8 – 3Encoder 8 inputs: 𝒀𝟕, 𝒀𝟔, 𝒀𝟓, 𝒀𝟒, 𝒀𝟑, 𝒀𝟐, 𝒀𝟏, 𝒀𝟎 3 outputs: 𝑨𝟐, 𝑨𝟏, 𝑨𝟎 𝒀𝟕 𝒀𝟓 𝑨𝟐 𝒀𝟒 𝒀𝟔 𝑨𝟏 Block diagram 𝒀𝟑 𝒀𝟐 𝒀𝟏 𝒀𝟎 4 - 2 ENCODER 𝑨𝟎 8 - 3 ENCODER
- 11. SLIDESMANIA.COM 8 – 3Encoder 8 inputs: 𝒀𝟕, 𝒀𝟔, 𝒀𝟓, 𝒀𝟒, 𝒀𝟑, 𝒀𝟐, 𝒀𝟏, 𝒀𝟎 3 outputs: 𝑨𝟐, 𝑨𝟏, 𝑨𝟎 0 0 0 0 0 0 Block diagram 0 0 1 0 4 - 2 ENCODER 1 8 - 3 ENCODER
- 12. SLIDESMANIA.COM 8 – 3Encoder Truth Table INPUTS OUTPUTS 𝑌7 𝑌6 𝑌5 𝑌4 𝑌3 𝑌2 𝑌1 𝑌0 𝐴3 𝐴2 𝐴0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 1 0 1 0 1 0 0 0 0 0 0 1 1 0 1 0 0 0 0 0 0 0 1 1 1
- 13. SLIDESMANIA.COM Boolean functions 𝐴2 =𝑌7 + 𝑌6 + 𝑌5 + 𝑌4 𝐴1 = 𝑌7 + 𝑌6 + 𝑌3 + 𝑌2 Circuit diagram
- 14. SLIDESMANIA.COM Drawbacks of Encoder •When all outputs of encoder are equal to zero. • If more than one input is active High, then the encoder produces an output, which may not be the correct code.
- 15.
- 16. SLIDESMANIA.COM 4 – 2Priority Encoder Truth Table INPUTS OUTPUTS Y3 Y2 Y1 Y0 A1 A0 V 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 X 1 0 1 0 1 X X 0 1 1 1 X X X 1 1 1 X equals “dont care”, that is it can be at a logic “0” level or at a logic “1” level
- 17. SLIDESMANIA.COM 4 – 3Priority Encoder INPUTS OUTPUTS Y3 Y2 Y1 Y0 A1 A0 V 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 X 1 0 1 0 1 X X 0 1 1 1 X X X 1 1 1 Lowest priority Highest priority To check the output is valid or not
- 18. SLIDESMANIA.COM 4 variable K-maps Booleanfunctions A1 = Y3 + Y2 A0 = Y3 + Y2’Y1 Boolean function of output, V V = Y3 + Y2 + Y1 + Y0
- 19.
- 20.